Configuring the ARM710T Header Card
© Copyright ARM Limited 1999. All rights reserved.
3-7
3.5
Setting the endianness
The ARM710T header card can be configured for either little-endian or big-endian
operation. The factory setting is for little-endian operation.
3.5.1
Little-endian memory system
To configure the ARM710T header card for little-endian operation:
1.
Remove BIGEND link (LK4) on the ARM development board.
2.
Reset the ARM710T. It automatically assumes a little-endian memory system, so
no software configuration is required.
3.5.2
Big-endian memory system
To configure the ARM710T header card for big-endian operation:
1.
Fit BIGEND link (LK4) on the ARM development board.
2.
Reset the ARM710T. It automatically assumes a little-endian memory system.
3.
Change the ARM710T to BIGEND mode by setting bit 7 of coprocessor 15
register 1, see Example 3-1.
Note
Any byte accesses before this bit is set will be little-endian so will not access the
expected data.
Example 3-1 Setting the ARM710T into BIGEND mode
MRC p15,0,r0,c1,0 ; read coprocessor 15 register 1
ORR r0,r0,#0x80
; set bit 7
MCR p15,0,r0,c1,0 ; write coprocessor 15 register 1
